#include <REGX52.H>
#include <intrins.h>
sbit Buzzer=P2^5;

void Buzzer_Delay500us()		//@12.000MHz
{
	unsigned char i;

	_nop_();
	i = 247;
	while (--i);
}

void Buzzer_a(unsigned int ms)
{
	unsigned char i;
	
	
  for(i=0;i<ms*2;i++)
	{
		Buzzer=~Buzzer;
		Buzzer_Delay500us();
	}	
}